Genetic Control of Flowering Traits, Yield and its Components in Maize (Zea mays L.) at Different Sowing Dates

2010 ◽  
Vol 2 (4) ◽  
pp. 236-249 ◽  
Author(s):  
Manal Hefny
1983 ◽  
Vol 25 (3) ◽  
pp. 270-277 ◽  
Author(s):  
Kitisri Sukhapinda ◽  
Peter A. Peterson

A case of cross-incompatibility among crosses in our genetics nursery was first observed in 1975. These crosses though involving controlling elements in maize (Zea mays L.) do not necessarily implicate these elements. When the derivative genotypes from the genetic stocks were crossed by specific male parents, ears with reduced seed set (RSS) were produced. In the reciprocal cross where these same genetic stocks were used as the male parent, ears with normal seed set (NSS) were obtained. The RSS effect is a heritable character caused by an incompatibility interaction between the female tissue and a specific pollen type. The genetic control of the incompatibility interaction has been hypothesized to be influenced by a cytoplasmic–chromosomal interaction in the female and a chromosomal factor in the pollen. The site of the incompatibility interaction is not on the silk surface because the incompatible pollen germinated and developed normally on the silk surface. Thus, the incompatibility interaction can occur either inside the silk or the ovule.


2018 ◽  
Vol 17 (2) ◽  
pp. 317
Author(s):  
ADILSON RICKEN SCHUELTER ◽  
MAYARA FABIANA SILVA ◽  
JONATAS MARCOLIN ◽  
IVAN SCHUSTER ◽  
ISABEL PRAZERES DE SOUZA

 RESUMO - As plantas daninhas constituem um dos fatores que reduzem a produtividade do milho e, portanto, é importante conhecer o mecanismo de tolerância da cultura aos herbicidas, de forma a fornecer informações que minimizem os riscos de danos aos cultivos. Dessa forma, o objetivo do trabalho foi avaliar a resposta de linhagens de milho e o controle genético envolvido na tolerância aos herbicidas nicosulfuron e tembotrione. Duzentas e cinco linhagens de milho foram avaliadas quanto à reação aos herbicidas. Para a avaliação do controle genético de tolerância aos herbicidas foram empregadas duas linhagens tolerantes e duas sensíveis, as quais foram intercruzadas empregando um dialelo de meia tabela. As linhagens e as populações oriundas desses cruzamentos foram avaliadas quanto à reação aos herbicidas em delineamento de blocos casualizados com quatro repetições. As dosagens foram de 60 g ha-1 de nicosulfuron (Sanson®) e 100 g ha-1 de tembotrione (Soberan®). A avaliação fenotípica constituiu-se de número de plantas sensíveis e/ou tolerantes e o teste do Qui-quadrado (χ2) foi utilizado nas análises. Quanto à resposta à aplicação dos agroquímicos verificaram-se linhagens tolerantes ou sensíveis a ambos os herbicidas ou apenas a um deles. Nas avaliações do controle genético, as análises evidenciaram um gene com dominância completa que, pela análise de segregação das famílias F3, permitiu levantar a hipótese de genes fortemente ligados ou pleiotrópicos. Os resultados obtidos, associados ao retrocruzamento assistido por marcadores moleculares (RCAM), auxiliaram o processo de introgressão da tolerância nas linhagens sensíveis aos herbicidas nicosulfuron e tembotrione.Palavras-chave: Zea mays L., herança, melhoramento genético, marcadores moleculares.GENETIC TOLERANCE OF MAIZE LINES TO TEMBOTRIONE AND NICOSULFURON ABSTRACT - As weeds are one of the factors that reduce maize productivity it is important to know the mechanism of crop tolerance to herbicide in order to minimize the risk of damage to the plants. Thus, the objective of this work was to evaluate the response of maize inbred lines and the genetic control of the tolerance to the herbicides nicosulfuron and tembotrione. Two hundred and five maize inbred lines were evaluated for herbicides reaction. For the evaluation of the genetic control of tolerance to herbicides, two tolerant and two sensitive inbred lines were used, which were intercrossed using a half diallel table. The inbred lines and the populations obtained from these crosses were evaluated for reaction to the herbicides in a randomized complete block design with 4 replicates. The dosages were 60 g ha-1 of nicosulfuron (Sanson™) and 100 g ha-1 of tembotrione (Soberan™). The phenotypic evaluation was based on the number of sensitive and / or tolerant plants and the chi-square test (χ2) was used in the analysis. Regarding the response to the application of the agrochemicals, inbred lines were tolerant or sensitive to one or both herbicides. The analysis of genetic control showed a gene with complete dominance, and the segregation analysis of the F3 families hypothesized the occurrence of strongly linked or pleiotropic genes. The data obtained associated to marker-assisted backcrossing allowed the tolerance introgression in sensitive inbred lines to nicosulfuron and tembotrione.Keywords: Zea mays L., inheritance, plant breeding, molecular markers.


Crop Science ◽  
1969 ◽  
Vol 9 (6) ◽  
pp. 739-741 ◽  
Author(s):  
John E. Ayers ◽  
Roy G. Creech
Keyword(s):  
Zea Mays ◽  

2021 ◽  
Vol 186 (2) ◽  
pp. 183-199
Author(s):  
Sevda KILINÇ ◽  
Şehmus ATAKUL ◽  
Şerif KAHRAMAN ◽  
Hüsnü AKTAŞ ◽  
İrfan ERDEMCİ ◽  
...  

This study was carried out to investigate the effects of different sowing times on duration of tasselling, plant height, first ear height, ear length, ear diameter, number of ears per plant, fresh ear yield with husk, fresh ear yield unhusked, and marketable number of ears of different sweet corn (Zea mays L. saccharata Sturt.) varieties in Diyarbakır between the years of 2010-2012. The trial was conducted as split plots in randomised complete blocks with three replications. The main plots were sowing times, and the sub-plots were varieties. The trials were carried out at eight different sowing times (1 April, 15 April, 1 May, 15 May, 1 June, 15 June, 1 July and 15 July) with ‘Merit’, ‘Jubilee’, ‘Lumina’, ‘Vega’ and ‘Sakarya’ composite sweet corn varieties. From the variance analysis of the three-year combined average, the duration of tasselling, plant height, first ear height, ear length, ear diameter, number of ears per plant, fresh husked ear yield, fresh unhusked ear yield and marketable ear number were statistically significant for sowing times and varieties. According to the sowing time × variety interaction, except ears per plant and first ear height values, all other traits were significant. The fresh husked and unhusked ear yields varied between 8541.7-19396.8 kg ha-1 and 5065.0-13485.7 kg ha-1, respectively. The highest fresh husked and fresh unhusked ear yields were obtained from the 15 April sowing time of ‘Vega’ variety. The results state that optimal sowing dates for different varieties of sweet corn could be from 1 April to 1 May, and the most suitable variety to be planted is ‘Vega’ in Diyarbakır conditions.


2021 ◽  
Vol 17 (2) ◽  
pp. 113-122
Author(s):  
Maksym Olkhovyk ◽  
Oleksandr Haidash ◽  
Yulyia Kupar ◽  
Mayna Tahantsova

Purpose. Comprehensive study, selection, evaluation and systematization of self-pollinated lines of maize (Zea mays L.) obtained on the basis of material of diffe­rent genetic structure from endosperm of flint and dent maize were implemented according to the main economically valuable traits and precocity in order to select the best genotypes for selection. Methods. Hybridization, inbreeding were used in the process of creating the initial material; visual method – for phenological observations; laboratory and field – to determine the morphobiological characteristics of self-pollinated lines of maize; measuring and weighing – to account the harvest and determine the metric characteristics of plants; mathematical and statistical – to determine the validity of the results, indicators of trait variability, correlation dependence of traits; analysis of variance; comprehensive assessment of morphobiological and economically valuable traits of self-pollinated maize lines of the most common germplasms. Results. As a result of assessment of self-pollinated lines of the most common germplasms, it was revealed that the highest level of grain yield was obtained under both sowing periods – Iodent germplasm; the minimum grain moisture content – Flint and Mix germplasms; the shortest average duration of the emergence – flowering of 50% of male and female inflorescences stage – Flint germplasm; steadily high va­lues ​​of plant height for germplasm Mix – under the optimal sowing date, and Iodent plasma – under the late sowing date. Steadily high values ​​of the ear insertion height at both sowing dates were obtained for lines based on Iodent germplasm. The number of the most precocious and the best by the economically valuable traits germplasms of self-pollinated lines were identified. Conclusions. The DK239 lines – Flint germplasm, DK7174, DK2285, DK305, DK2613, DK5568 – Iodent germplasm, DK2332 and DK2659 – Mix germplasm were the most precocious and the best by the economically valuable traits. They are promising for the selection of ultra-early hybrids of maize adapted to the conditions of the Steppe of Ukraine.


2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Dil Bahadur Gurung ◽  
Balram Bhandari ◽  
Jiban Shrestha ◽  
Mahendra Prasad Tripathi

Genotypic yield potential of maize varieties is greatly affected by sowing dates. In order to investigate the effects of sowing dates and varieties on the grain yield of maize, the field experiment was carried out at research field of National Maize Research Program (NMRP), Rampur, Chitwan, Nepal from April 2009 to March 2010.  Three varieties namely Rampur Composite, Arun-2 and Gaurav were sown at every week. The results of experiment showed that interaction effect of variety and sowing date on grain yield of maize was significant. Rampur Composite produced highest grain yield (6.1 t/ha) in August and lowest yield (2.6 t/ha) in May. Similarly Arun-2 produced highest yield (4.6 t/ha) in August and lowest yield (2.1 t/ha) in May. Gaurav produced highest grain yield (5.1 t/ha) in September followed by 4.9, 4.8 and 4.6 t/ha in February, July and August respectively and lowest yield (1.5 t/ha) in November. The sowing date was highly significant on grain production. The highest grain production was 5.1 t/ha in August followed by in February (4.9 t/ha), September (4.6 t/ha) and March (4.4 t/ha) respectively. The lowest grain yield was produced in May (2.4 t/ha). Therefore it was concluded that August planting was best for higher grain production of maize varieties (Rampur Composite, Arun-2 and Gaurav) in terai region of Nepal.


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